Device for relieving cutters



Jian. 23, i945. A, J. ENGLAND DEVIC FOR RELIEVING CUTTEBS Filed July l5,v19472 Patented Jan. 23, 1945 UNITED STATES PATENT oFFlcE DEVICE FORRELIEVIN G CUTTERS August J. England, Providence, R.. I. ApplicationJuly 15, 1942, Serial No. 451,018

.2 Claims.

This invention relates to a device for backing oli the teeth of cutters,or a relieving of the cutting teeth of cutters.'

In backing olf. the teeth of cutters it has been usual to perform thisVoperation on a special backing-off lathev attachment.

One of the objects of this-invention is to provide a simple, mechanicalarrangement which may be utilized for relieving or backing off cutters.

Another object of this invention is to provide an attachment for a lathewhich will enable cutters to be backed on or relieved satisfactorily.

Another object of this invention is to provide an arrangement whereby,with simple additions and changes, the mechanism usual on a lathe.

may be transformed into a device for relieving the cutting teeth ofcutters or backing oi cutters, as it is sometimes termed.

With these and other objects in View, the invention consists of certainnovel features f construction, as will be more fully described andparticularly pointed out in the appended claims.

In the accompanying drawing:

Fig. l is a sectional view taken laterally of a lathe and illustratingthe parts thereof modied to incorporate the present invention;

Fig. 2 is a top plan View of a fragmental portion of the parts shown inFig. 1;

Fig. 3 is a perspective View of a fragmental portion of the arm which isattached to the cross slide of the lathe;

Fig. 4 is a side view of the cam; and

Fig. 5 is a side View of the work which is performed upon the device.

In proceeding with this invention I have modifled the usual cross slideof a lathe by adding an arm thereto with a cam follower and so arrangingthe usual adjustment of the cross slide that a spring urges the slide ina direction to cause the follower to engage a cam and be governed by theshape of the cam. An arbor is mounted in the lathe between the headstock and tail stock and the controlling cam and work are mounted on thearbor. The remaining mechanism of the lathe is standard equipment.

With reference to the drawing, in Fig. 1 at I0 there is illustrated incross section, the bedof the lathe upon which the usual carriage II ispositioned which will slide longitudinally of the lathe along the guideI2. However, in the present instance, the carriage is rmly locked inposition on the bed i0. The carriage has provided thereon a dovetailguide I3 which directs the lateral movement across the lathe of thecross slide I4. The dovetail guide has a central slot through which theboss shown in dotted lines at I5 extends, which boss is threaded as 'atI1 for the reception of the shaft I8. The shaft extends through thecollar 2G which is fixed to the carriage II and is provided with a headI9.

This shaft I8 usually has mounted thereon a handle for rotating thesame, together with a collar and dial, but these have all been removedand replaced by a spring 2| which acts against a washer 22 just inwardlyof the head I9 while pressing on collar 2U to urge th-e cross slide I4toward the right as shown in Fig. 1 along its guide I3. As illustrated,the shaft I8 which formerly rotated now is only rotated for adjustmentof the tension of the spring 2I, and after this tension is adjusted to asuitable amount, the shaft moves With the cross slide as if a xed partthereof.

Attached to the cross slide there is a bracketlike arm 25 (see Fig. 3)bolted to the side of the cross slide as at 26. This arm extends upwardand carries a cam follower 21 for engagement with a cam 28.

The cam 28 is mounted on an arbor 29 which is' positioned between thelive center 30 and the dead center 3I. The live center is mounted in ausual manner in a spindle 32 which is provided with a face plate 34 alldriven by the head stock 33. A dog 35 engages the face plate and isclamped to the arbor by means of a set screw 36. The dead center ismounted in the tail stock 3l in a usual manner. The detail of the headand tail stock of the lathe are not here illustrated. The work or cutter38 is mounted on the arbor 29 as is also the cam 28 which is to governthe movement of the tool for operating upon the work.

The cross slide I4 has mounted thereon a member 4D which may be adjustedswivelly on the cross slide, and upon this member the compound slide 4Iis secured for movement alo-ng the dovetail guide 42 by reason of thehandle 43 turning the threaded shaft 44 which is threaded into the boss45 xed to the member 40. Thug by turning a handle 43 the compound slide4I may be moved inwardly or outwardly with reference to the arbor. Thecompound slide has mounted Iherein in a usual manner the tool post 46and the tool holder 41 with a tool 48. Suitable binding means 49 and 50are provided in a usual manner.

In operation I will mount the work on the arbor and then mount a cam 28upon the arbor 29 in the reverse direction of the cutter which I desireto back oiT. Rotation of the head stock is corn- Lmenced and, as will beapparent, the follower 21 is drawn into engagement with the cam 28 bymeans of the spring 2|. The tool 48 is adjusted by means of the hande 43to take the proper depth cut and then as rotation occurs the cross slideis moved in and out in response to the cam to cause the ycutter toadvance toward or move from the arbor to back off each of the teeth ofthe cutter 38. As the operation occurs the tool may be fed inwardly bythe handle 43 from time to time after a complete revolution of thearbor' has been made one or more times until the proper amount ofbacking off of each of the teeth is accomplished.

By the arrangement of the cam follower 21 on one side of the arbor andthe cutting tool 48 on the other side of the arbor at substantiallydiametrically opposite points, should there be any spring in the arborinasmuch as these two parts 21 and 48 move together, no irregularitybecause of the spring of the arbor will occur in the work.

Iclaim:

l. Means for the conversion of a lathe, having an arbor driven from thespindle with a cutter to be relieved on said arbor, and a pattern platecoaxial therewith and a carriage having a crossslide thereon with ashaft to adjust the crossslide relative to the carriage, to a machinefor relieving a cutter, comprising a bracket attached to saidcross-slide and provided with a follower at a location to engage saidpattern plate and resilient means associated with said shaft and actingbetween said cross-slide and carriage to move said cross-slide to causesaid follower to press upon said pattern plate.

2. Means for the conversion of a lathe, having an arbor driven from thespindle With a cutter to be relieved on said arbor, and a pattern platecoaxial therewith and a carriage having a. crossslide thereon with ashaft to adjust the crossslide relative to the carriage, to a machinefor relieving a cutter, comprising an L-shaped upwardly extendingbracket attached to said crossslide and provided with a follower at alocation to engage said pattern plate and a spring encircling said shaftand acting between said crossslide and carriage to move saidIcross-slide to cause said follower to press upon said pattern plate.

AUGUST J. ENGLAND.

